The co-firing of animal biomass fuels with coal has the potential to solve both biomass disposal problems, and reduce net CO2 emissions. The high flame temperatures produced by coal will allow the low heating value, high ash biomass to be completely burnt. Unfortunately, the animal biomass fuels are high in nitrogen and sulfur, which could lead to greater air pollution levels in the form of NO and SO2. To determine the effect of switching to 90:10 Coal:biomass blend on combustion efficiency and emissions, the blends were fired in a 30 kW (100,000 BTU/hr) laboratory scale boiler burner. The results are presented along with the their relation to the fuel properties.